"In , only children ... may be adopted ... Adoption is usually associated with the desire to nurture and protect the child as if one's own, and s or illegitimate children are the most frequent candidates for adoption. ... This has little in common with adoption among the . ... Those given in adoption are mostly adults ... Very few adoptions are directly attested. Roman legal writings are one of our best sources of evidence for the actual practice of adoption among the Romans; inscriptions are insufficiently specific for certainty in detecting adoptions, and the adoptions mentioned in literary sources are numbered in tens rather than hundreds. There is even less direct evidence about the reasons for adoption. Of the adoptions that are mentioned in literary sources, those in successive imperial families are not entirely typical of Roman society at large, since they generally have a specifically dynastic and political purpose. As in private families, however, a definite preference is shown for adopting persons related by blood, or at least by marriage, where any are available. This is the case between and , among the and the , and is most evident among the ."